Seasonal study of nutrients and organic matter in first-year sea ice on the Mackenzie shelf

First-year sea ice was sampled on 36 occasions near the overwintering site of the CCGS Amundsen during the Canadian Arctic Shelf Exchange Study (CASES). Sea-ice and associated surface water samples were taken every 3 to 5 days between 24 February and 20 June 2004. Surface waters and the bottom 3-5 cm of ice cores were routinely analyzed for: salinity, pH, nutrients (NH4, NO2, NO3, Si(OH)4, and PO4), dissolved organic carbon and nitrogen (DOC, DON), exopolymeric substances (EPS), particulate inorganic carbon (PIC), particulate organic carbon and nitrogen (POC, PON), total and >5 µm chlorophyll a and phaeopigments, bacterial abundances/biomass, protist (excluding diatoms) abundances/biomass and ice algal/phytoplankton taxonomy. This data set also includes vertical and spatial profiles of ice algal distribution as well as measurements of sea-ice primary production, bacterivory and sea-ice algal and bacterial sinking velocities.